| Bioactive tetrapeptide PKEK, has proven skin-lightening benefits on skin discoloration from melasma and postinflammatory hyperpigmentation. The tetrapeptide PKEK can exert skin whitening effects based on one in vitro and four double-blinded vehicle-controlled in vivo studies. PKEK treatment significantly inhibited UVB-induced upregulation of genes encoding for IL-1 alpha, IL-6, IL-8, TNF-alpha as well as POMC and tyrosinase in healthy volunteers. |
